Applying a system of a bolt and a nut for fastening purposes has already been known for several centuries. Although bolts and nuts can be embodied in diverse ways, the bolt is generally formed by a round rod which is provided with a thickened head and on the outside of which a screw thread profile is arranged, and the nut is generally formed by a ring, the outer side of which generally takes an angular form and the inner side of which is provided with a complementary screw thread profile. A relatively durable and strong screw thread connection between the bolt and the nut can be realized by arranging the nut round the bolt by means of axial rotation. Although the realized connection is generally considered as such to be sufficiently strong, it is a drawback of the known nut-bolt connection that, particularly in the case a relatively long bolt is applied, realizing the screw thread connection is relatively time-consuming.
Diverse solutions have been proposed for the purpose of realizing a quicker threaded connection. The screw thread on one of the fastening elements, usually the nut, is replaced here by a number of protrusions in radial direction. The bolt can be pulled along the protrusions to a desired position.
U.S. Pat. No. 5,451,124 discloses wire-like protrusions in the form of a wire brush. The protrusions are fixed in a holder on an outer ring and are directed toward a central axis. Because these protrusions are longer than the distance between the bolt and the outer ring, they will bend when the bolt is pulled along the protrusions. The wire-like protrusions herein come to lie in the groove of the screw thread. Since they all bend in one direction, this creates resistance to translation in the reverse direction. The drawback of such wire-like protrusions is however the lack of force applied. The eventual threaded connection is thus of a far lesser quality than the conventional screw thread connection.
GB 2,308,154 discloses a construction with a number of flexible, resilient protrusions or tabs adjacently of each other in the peripheral direction. These tabs are ordered in two rows and at a mutual distance of 1/12th of the pitch of the thread. They are oriented inclining inward such that, when one tab engages in the screw thread profile (i.e. the groove thereof) in the natural state, the other protrusions are not fully engaged in the screw thread profile. During tightening of the nut the other tabs will bend and engage further in the screw thread profile. This construction has the drawback, among others, that the placing of the tabs depends on the specific screw thread profile. The tabs can here spring loose of the screw thread profile or not become properly secured, for instance when the screw thread has been damaged.
Other solutions, such as those of DE 19929016, NL 1014082 and EP 1217230, are based on the principle of a barb. It is even more the case here than in GB 2,308,154 that the screw thread is fixed by curved protrusions (hooks) on the outer ring. A number of protrusions are available in the longitudinal direction. The risk of such constructions is that the protrusion breaks off when force is applied thereto.
An object of the invention is to provide a system of complementary fastening elements, using which a screw thread connection can be realized relatively quickly and wherein the screw thread connection has a strength which is comparable to that of a conventional screw thread connection and is thereby suitable for the same applications, including professional applications such as construction and machinery.